[en] Collection of empirical data and data base development for use in the prediction of the probability of future events has a long history. Dating back at least to the 17th century, safe passage events and mortality events were collected and analyzed to uncover prospective underlying classes and associated class attributes. Tabulations of these developed classes and associated attributes formed the underwriting basis for the fledgling insurance industry. Much earlier, master masons and architects used design rules of thumb to capture the experience of the ages and thereby produce structures of incredible longevity and reliability (Antona, E., Fragola, J. and Galvagni, R. Risk based decision analysis in design. Fourth SRA Europe Conference Proceedings, Rome, Italy, 18-20 October 1993). These rules served so well in producing robust designs that it was not until almost the 19th century that the analysis (Charlton, T.M., A History Of Theory Of Structures In The 19th Century, Cambridge University Press, Cambridge, UK, 1982) of masonry voussoir arches, begun by Galileo some two centuries earlier (Galilei, G. Discorsi e dimostrazioni mathematiche intorno a due nuove science, (Discourses and mathematical demonstrations concerning two new sciences, Leiden, The Netherlands, 1638), was placed on a sound scientific basis. Still, with the introduction of new materials (such as wrought iron and steel) and the lack of theoretical knowledge and computational facilities, approximate methods of structural design abounded well into the second half of the 20th century. To this day structural designers account for material variations and gaps in theoretical knowledge by employing factors of safety (Benvenuto, E., An Introduction to the History of Structural Mechanics, Part II: Vaulted Structures and Elastic Systems, Springer-Verlag, NY, 1991) or codes of practice (ASME Boiler and Pressure Vessel Code, ASME, New York) originally developed in the 19th century (Antona, E., Fragola, J. and Galvagni, R. Risk based decision analysis in design. Fourth SRA Europe Conference Proceedings, Rome, Italy, 18-20 October 1993). These factors, although they continue to be heuristically based, attempt to account for uncertainties in the design environment (e.g., the load spectra) and residual materials defects (Fragola, J.R. et al., Investigation of the risk implications of space shuttle solid rocket booster chamber pressure excursions. SAIC Document No. SAIC/NY 95-01-10, New York, NY). Although the approaches may appear different, at least at first glance, the intention in both the insurance and design arenas was to establish an 'infrastructure of confidence' to enable rational decision making for future endeavours. Maturity in the design process of conventional structures such as bridges, buildings, boilers, and highways has led to the loss of recognition of the role that robustness plays in these designs to qualify them against their normal failure environment. So routinely do we expect these designs to survive that we tend to think of the individual failures (which do occur on occasion) as isolated 'freak' accidents. Attempts to uncover potential underlying classes and document associated attributes are rare, and even when they are undertaken 'human error' or 'one-of-a-kind accidents' is often cited as the major cause which somehow seems to absolve the analyst from the responsibility of further data collection (Levy, M. and Salvadori, M., Why Buildings Fall Down, W.W. Norton and Co., New York, NY, 1992; Pecht, M., Nash, F.R. and Long, J.H., Understanding and solving the real reliability assurance problems. 1995 Proceedings of Annual RAMS Symposium, IEEE, New York, NY, 1995). The confusion has proliferated to the point where legitimate calls for scepticism regarding the scant data resources available (Evans, R.A., Bayes paradox. IEEE Trans. Reliab., R-31 (1982) 321) have given way to cries that some data sources be abandoned altogether (Cushing, M. et al., Comparison of electronics-reliability assessment approaches. Trans. Reliab., 42 (1993) 542-546 Wat son, G.F., MIL Reliability: a new approach. IEEE Spectrum, 29 (1992) 46-49). Authors who have suggested that the concept of generic data collection be abolished in favor of a physics-of-failure approach (Watson, G.F., MIL Reliability: a new approach. IEEE Spectrum, 29 (1992) 46-49) now seem to be suggesting that the concept of 'failure rate' be banished altogether and with it the concept of reliability prediction (Pecht., M. and Nash, F., Predicting the reliability of electronic equipment. Proc. IEEE, 82 (1994) 992-1004). There can be no doubt that abuses of generic data exist and that the physics-of-failure approach has merit, especially in design development, however, does the situation really justify the abandonment of the collection, analysis, and classification of empirical failure data and the elimination of reliability or risk prediction? If not, can the concepts of 'failure rate' and 'prediction' be redefined so as to allow for meaningful support to be provided to logical decision making? This paper reviews both the logical and historical context within which reliability and risk data bases have been developed so as to generate an understanding of the motivations for and the assumptions underlying their development. Further, an attempt is made to clarify what appears to be fundamental confusion in the field of reliability and risk analysis. With these clarifications in hand, a restructuring of the conceptual basis for reliability data base development and reliability predictions is suggested, and some hopeful recent developments are reported upon

[en] The subject of my lecture is the use of nuclear energy for sea water desalination. During this study course this is the only lecture we will have on desalination and therefore we have many points to cover. I propose to cover these points in the following order: (1) Determining the feasibility, of nuclear desalination (2) Nuclear desalination and plant cycles (3) Additional nuclear desalination plant considerations and recent desalination developments. In several cases, whore there is only time for a summary, there is a more complete treatment in the Appendices.

[en] The food irradiation debate it is seen as a very complex and the controversy itself, multi-faceted. Disputes over scientific facts are only one aspect of the debate and once this is recognized, the essentially political nature of the food irradiation debate can be acknowledged. Strategic positioning and rhetorical argument are indispensable, especially in the realm of public debate, since the misinformation promulgated by opponents are often left unanswered by experts in the field. 4 refs., ills

[en] While working with E.O. Lawrence at Berkeley, R.R. Wilson in 1946 noted the potential for using the Bragg-peak of protons (or heavier ions) for radiation therapy. Thus began the long history of contributions from Berkeley to this field. Pioneering work by C.A. Tobias et al at the 184-Inch Synchrocyclotron led ultimately to clinical applications of proton and helium beams, with over 1000 patients treated through 1974 with high-energy plateau radiation; placing the treatment volume (mostly pituitary fields) at the rotational center of a sophisticated patient positioner. In 1974 the SuperHILAC and Bevatron accelerators at the Lawrence Berkeley Laboratory were joined by the construction of a 250-meter transfer line, forming the Bevalac, a facility capable of accelerating ions of any atomic species to relativistic energies. With the advent of these new beams, and better diagnostic tools capable of more precise definition of tumor volume and determination of the stopping point of charged-particle beams, large-field Bragg-peak therapy with ion beams became a real possibility. A dedicated Biomedical experimental area was developed, ultimately consisting of three distinct irradiation stations; two dedicated to therapy and one to radiobiology and biophysics. These facilities included dedicated support areas for patient setup and staging of animal and cell samples, and a central control area linked to the main Bevatron control room

[en] This paper describes the application of Fault Tree Analysis to the design phase of a robot manipulator for hazardous waste retrieval. The robot is to be deployed in single-shell under-ground storage tanks at the US Department of Energy (DOE) site in Hanford, Washington. These tanks contain a variety of highly radioactive waste types, necessitating extremely safe and reliable manipulator operation. Based on preliminary design drawings of this long-reach manipulator, fault trees were constructed for several critical failure scenarios. Analysis of the trees revealed a number of ways to improve the safety and reliability of the manipulator design. This paper presents a summary of the fault tree analysis, with a discussion of the applicability of qualitative and quantitative fault tree methods to hazardous waste robotics

[en] An environmental geochemistry approach was applied in response to health concerns about present day and past exposure to pollutants within Broome County, New York by determining historical records of anthropogenic activities as preserved in sediment cores. Sediment was collected from a stormwater retention pond adjacent to a warehouse complex in the urban community of Hillcrest as well as from 3 other ponds in rural locations in Broome County. Metal concentrations and decay products of ²¹⁰Pb and ¹³⁷Cs were measured to determine the timing of source specific differences in the distribution of metals in the sediment cores. Concentrations of Zn, Pb, Ni, Cu, Cr, Cd and As were elevated in the retention pond sediments when compared to sediment from other locations. Topography influenced atmospheric transport and deposition of pollutants within incised river valleys and enhanced runoff from impervious surfaces within an urban watershed contributed to the elevated metal concentrations at Hillcrest. Temporal changes in Pb deposition within retention pond sediment mimic the rise and fall in use of leaded gasoline. Arsenic concentrations decreased following placement of emission controls on nearby coal-fired power plant sources. Superimposed over the temporal trends of Pb and As are co-varying Zn, Ni, Cu, Cr and Cd concentrations; a suite of metals commonly used in metal plating processes by local industries. Analysis of sediment in stormwater retention ponds in other urban areas may provide opportunities for detailed records of pollution history to be obtained in many communities. Residents in urban communities located in incised river valley locations similar to Hillcrest may be particularly prone to enhanced exposure to metals from anthropogenic sources

[en] The angle of ion incidence at the etched wafer location during RIBE and IBE using Cl₂, Ar and O₂ ion beams has been characterized using an ion energy and angle analyzer. Effects of beam current and accelerator grid bias on beam divergence and the spatial uniformity of the spread of incident angles are measured. It is observed that increased total beam current can lead to reduced current density at the sample stage due to enhanced beam divergence at high currents. Results are related to preferred etch system design for uniform high-aspect-ratio etching across semiconductor wafers

[en] This report documents measurements in inductively driven plasmas containing SF(sub 6)/Argon gas mixtures. The data in this report is presented in a series of appendices with a minimum of interpretation. During the course of this work we investigated: the electron and negative ion density using microwave interferometry and laser photodetachment; the optical emission; plasma species using mass spectrometry, and the ion energy distributions at the surface of the rf biased electrode in several configurations. The goal of this work was to assemble a consistent set of data to understand the important chemical mechanisms in SF(sub 6) based processing of materials and to validate models of the gas and surface processes

[en] An overall trend toward smaller electronic packages and devices makes it increasingly important and difficult to obtain meaningful diffraction information from small areas. X-ray micro-diffraction, electron back-scattered diffraction (EBSD) and Kossel are micro-diffraction techniques used for crystallographic analysis including texture, phase identification and strain measurements. X-ray micro-diffraction primarily is used for phase analysis and residual strain measurements. X-ray micro-diffraction primarily is used for phase analysis and residual strain measurements of areas between 10 microm to 100 microm. For areas this small glass capillary optics are used for producing a usable collimated x-ray beam. These optics are designed to reflect x-rays below the critical angle therefore allowing for larger solid acceptance angle at the x-ray source resulting in brighter smaller x-ray beams. The determination of residual strain using micro-diffraction techniques is very important to the semiconductor industry. Residual stresses have caused voiding of the interconnect metal which then destroys electrical continuity. Being able to determine the residual stress helps industry to predict failures from the aging effects of interconnects due to this stress voiding. Stress measurements would be impossible using a conventional x-ray diffractometer; however, utilizing a 30 microm glass capillary these small areas are readily assessable for analysis. Kossel produces a wide angle diffraction pattern from fluorescent x-rays generated in the sample by an e-beam in a SEM. This technique can yield very precise lattice parameters for determining strain. Fig. 2 shows a Kossel pattern from a Ni specimen. Phase analysis on small areas is also possible using an energy dispersive spectrometer (EBSD) and x-ray micro-diffraction techniques. EBSD has the advantage of allowing the user to observe the area of interest using the excellent imaging capabilities of the SEM. An EDS detector has been used for simultaneous element identification which enhances phase identification of unknowns. The x-ray area detector also allows for rapid microstructure information including crystallite orientation and size by directly observing the diffraction rings. These techniques allow for small area analysis that in the past would have been difficult if not impossible to obtain. The future development in x-ray optics and the use of synchrotron sources will allow for the potential of nondestructive submicron x-ray diffraction analysis

[en] Highlights: • Dry drilled, uncontaminated cuttings from Marcellus Shale and surrounding units. • Unoxidized and oxidized samples leached short and long term with H_2O or dilute HCl. • Pb isotope ratios have distinctly different values from Marcellus Shale samples. • Mo and other trace metals can be used as Marcellus Shale environmental tracers. • Marcellus Shale leachate concentrations can exceed EPA contaminant screening levels. - Abstract: Drill cuttings generated during unconventional natural gas extraction from the Marcellus Shale, Appalachian Basin, U.S.A., generally contain a very large component of organic-rich black shale because of extensive lateral drilling into this target unit. In this study, element concentrations and Pb isotope ratios obtained from leached drill cuttings spanning 600 m of stratigraphic section were used to assess the potential for short and long term environmental impacts from Marcellus Shale waste materials, in comparison with material from surrounding formations. Leachates of the units above, below and within the Marcellus Shale yielded Cl/Br ratios of 100–150, similar to produced water values. Leachates from oxidized and unoxidized drill cuttings from the Marcellus Shale contain distinct suites of elevated trace metal concentrations, including Cd, Cu, Mo, Ni, Sb, U, V and Zn. The most elevated Mo, Ni, Sb, U, and V concentrations are found in leachates from the lower portion of the Marcellus Shale, the section typically exploited for natural gas production. In addition, lower "2"0"7Pb/"2"0"6Pb ratios within the lower Marcellus Shale (0.661–0.733) provide a distinctive fingerprint from formations above (0.822–0.846) and below (0.796–0.810), reflecting "2"0"6Pb produced as a result of in situ "2"3"8U decay within this organic rich black shale. Trace metal concentrations from the Marcellus Shale leachates are similar to total metal concentrations from other black shales. These metal concentrations can exceed screening levels recommended by the EPA, and thus have the potential to impact soil and water quality depending on cuttings disposal methods